Team Ai
Apppublic

xdecoder/Instruct-X-Decoder

sourceHugging Faceafl-3.0updated 3y agoView on Hugging Face
163likes
focal.py692 linesDownload Raw Back to backbone
1# --------------------------------------------------------2# FocalNet for Semantic Segmentation3# Copyright (c) 2022 Microsoft4# Licensed under The MIT License [see LICENSE for details]5# Written by Jianwei Yang6# --------------------------------------------------------7import math8import time9import numpy as np10import logging11import torch12import torch.nn as nn13import torch.nn.functional as F14import torch.utils.checkpoint as checkpoint15from timm.models.layers import DropPath, to_2tuple, trunc_normal_16 17from detectron2.utils.file_io import PathManager18from detectron2.modeling import BACKBONE_REGISTRY, Backbone, ShapeSpec19 20from .registry import register_backbone21 22logger = logging.getLogger(__name__)23 24class Mlp(nn.Module):25    """ Multilayer perceptron."""26 27    def __init__(self, in_features, hidden_features=None, out_features=None, act_layer=nn.GELU, drop=0.):28        super().__init__()29        out_features = out_features or in_features30        hidden_features = hidden_features or in_features31        self.fc1 = nn.Linear(in_features, hidden_features)32        self.act = act_layer()33        self.fc2 = nn.Linear(hidden_features, out_features)34        self.drop = nn.Dropout(drop)35 36    def forward(self, x):37        x = self.fc1(x)38        x = self.act(x)39        x = self.drop(x)40        x = self.fc2(x)41        x = self.drop(x)42        return x43 44class FocalModulation(nn.Module):45    """ Focal Modulation46 47    Args:48        dim (int): Number of input channels.49        proj_drop (float, optional): Dropout ratio of output. Default: 0.050        focal_level (int): Number of focal levels51        focal_window (int): Focal window size at focal level 152        focal_factor (int, default=2): Step to increase the focal window53        use_postln (bool, default=False): Whether use post-modulation layernorm54    """55 56    def __init__(self, dim, proj_drop=0., focal_level=2, focal_window=7, focal_factor=2, use_postln=False, use_postln_in_modulation=False, scaling_modulator=False):57 58        super().__init__()59        self.dim = dim60 61        # specific args for focalv362        self.focal_level = focal_level63        self.focal_window = focal_window64        self.focal_factor = focal_factor65        self.use_postln_in_modulation = use_postln_in_modulation66        self.scaling_modulator = scaling_modulator67 68        self.f = nn.Linear(dim, 2*dim+(self.focal_level+1), bias=True)69        self.h = nn.Conv2d(dim, dim, kernel_size=1, stride=1, padding=0, groups=1, bias=True)70 71        self.act = nn.GELU()72        self.proj = nn.Linear(dim, dim)73        self.proj_drop = nn.Dropout(proj_drop)74        self.focal_layers = nn.ModuleList()75 76        if self.use_postln_in_modulation:77            self.ln = nn.LayerNorm(dim)78 79        for k in range(self.focal_level):80            kernel_size = self.focal_factor*k + self.focal_window81            self.focal_layers.append(82                nn.Sequential(83                    nn.Conv2d(dim, dim, kernel_size=kernel_size, stride=1, groups=dim, 84                        padding=kernel_size//2, bias=False),85                    nn.GELU(),86                    )87                )88 89    def forward(self, x):90        """ Forward function.91 92        Args:93            x: input features with shape of (B, H, W, C)94        """95        B, nH, nW, C = x.shape96        x = self.f(x)97        x = x.permute(0, 3, 1, 2).contiguous()98        q, ctx, gates = torch.split(x, (C, C, self.focal_level+1), 1)99        100        ctx_all = 0101        for l in range(self.focal_level):                     102            ctx = self.focal_layers[l](ctx)103            ctx_all = ctx_all + ctx*gates[:, l:l+1]104        ctx_global = self.act(ctx.mean(2, keepdim=True).mean(3, keepdim=True))105        ctx_all = ctx_all + ctx_global*gates[:,self.focal_level:]106 107        if self.scaling_modulator:108            ctx_all = ctx_all / (self.focal_level + 1)109 110        x_out = q * self.h(ctx_all)111        x_out = x_out.permute(0, 2, 3, 1).contiguous()112        if self.use_postln_in_modulation:113            x_out = self.ln(x_out)            114        x_out = self.proj(x_out)115        x_out = self.proj_drop(x_out)116        return x_out117 118class FocalModulationBlock(nn.Module):119    """ Focal Modulation Block.120 121    Args:122        dim (int): Number of input channels.123        mlp_ratio (float): Ratio of mlp hidden dim to embedding dim.124        drop (float, optional): Dropout rate. Default: 0.0125        drop_path (float, optional): Stochastic depth rate. Default: 0.0126        act_layer (nn.Module, optional): Activation layer. Default: nn.GELU127        norm_layer (nn.Module, optional): Normalization layer.  Default: nn.LayerNorm128        focal_level (int): number of focal levels129        focal_window (int): focal kernel size at level 1130    """131 132    def __init__(self, dim, mlp_ratio=4., drop=0., drop_path=0., 133                 act_layer=nn.GELU, norm_layer=nn.LayerNorm,134                 focal_level=2, focal_window=9, 135                 use_postln=False, use_postln_in_modulation=False,136                 scaling_modulator=False, 137                 use_layerscale=False, 138                 layerscale_value=1e-4):139        super().__init__()140        self.dim = dim141        self.mlp_ratio = mlp_ratio142        self.focal_window = focal_window143        self.focal_level = focal_level144        self.use_postln = use_postln145        self.use_layerscale = use_layerscale146 147        self.norm1 = norm_layer(dim)148        self.modulation = FocalModulation(149            dim, focal_window=self.focal_window, focal_level=self.focal_level, proj_drop=drop, use_postln_in_modulation=use_postln_in_modulation, scaling_modulator=scaling_modulator150        )            151 152        self.drop_path = DropPath(drop_path) if drop_path > 0. else nn.Identity()153        self.norm2 = norm_layer(dim)154        mlp_hidden_dim = int(dim * mlp_ratio)155        self.mlp = Mlp(in_features=dim, hidden_features=mlp_hidden_dim, act_layer=act_layer, drop=drop)156 157        self.H = None158        self.W = None159 160        self.gamma_1 = 1.0161        self.gamma_2 = 1.0162        if self.use_layerscale:163            self.gamma_1 = nn.Parameter(layerscale_value * torch.ones((dim)), requires_grad=True)164            self.gamma_2 = nn.Parameter(layerscale_value * torch.ones((dim)), requires_grad=True)165 166    def forward(self, x):167        """ Forward function.168 169        Args:170            x: Input feature, tensor size (B, H*W, C).171            H, W: Spatial resolution of the input feature.172        """173        B, L, C = x.shape174        H, W = self.H, self.W175        assert L == H * W, "input feature has wrong size"176 177        shortcut = x178        if not self.use_postln:179            x = self.norm1(x)180        x = x.view(B, H, W, C)181        182        # FM183        x = self.modulation(x).view(B, H * W, C)184        if self.use_postln:185            x = self.norm1(x)186 187        # FFN188        x = shortcut + self.drop_path(self.gamma_1 * x)189 190        if self.use_postln:191            x = x + self.drop_path(self.gamma_2 * self.norm2(self.mlp(x)))192        else:193            x = x + self.drop_path(self.gamma_2 * self.mlp(self.norm2(x)))194 195        return x196 197class BasicLayer(nn.Module):198    """ A basic focal modulation layer for one stage.199 200    Args:201        dim (int): Number of feature channels202        depth (int): Depths of this stage.203        mlp_ratio (float): Ratio of mlp hidden dim to embedding dim. Default: 4.204        drop (float, optional): Dropout rate. Default: 0.0205        drop_path (float | tuple[float], optional): Stochastic depth rate. Default: 0.0206        norm_layer (nn.Module, optional): Normalization layer. Default: nn.LayerNorm207        downsample (nn.Module | None, optional): Downsample layer at the end of the layer. Default: None208        focal_level (int): Number of focal levels209        focal_window (int): Focal window size at focal level 1210        use_conv_embed (bool): Use overlapped convolution for patch embedding or now. Default: False211        use_checkpoint (bool): Whether to use checkpointing to save memory. Default: False212    """213 214    def __init__(self,215                 dim,216                 depth,217                 mlp_ratio=4.,218                 drop=0.,219                 drop_path=0.,220                 norm_layer=nn.LayerNorm,221                 downsample=None,222                 focal_window=9, 223                 focal_level=2, 224                 use_conv_embed=False,     225                 use_postln=False,          226                 use_postln_in_modulation=False, 227                 scaling_modulator=False,228                 use_layerscale=False,                   229                 use_checkpoint=False230        ):231        super().__init__()232        self.depth = depth233        self.use_checkpoint = use_checkpoint234 235        # build blocks236        self.blocks = nn.ModuleList([237            FocalModulationBlock(238                dim=dim,239                mlp_ratio=mlp_ratio,240                drop=drop,241                drop_path=drop_path[i] if isinstance(drop_path, list) else drop_path,242                focal_window=focal_window, 243                focal_level=focal_level, 244                use_postln=use_postln, 245                use_postln_in_modulation=use_postln_in_modulation, 246                scaling_modulator=scaling_modulator,247                use_layerscale=use_layerscale, 248                norm_layer=norm_layer)249            for i in range(depth)])250 251        # patch merging layer252        if downsample is not None:253            self.downsample = downsample(254                patch_size=2,255                in_chans=dim, embed_dim=2*dim, 256                use_conv_embed=use_conv_embed, 257                norm_layer=norm_layer, 258                is_stem=False259            )260 261        else:262            self.downsample = None263 264    def forward(self, x, H, W):265        """ Forward function.266 267        Args:268            x: Input feature, tensor size (B, H*W, C).269            H, W: Spatial resolution of the input feature.270        """271        for blk in self.blocks:272            blk.H, blk.W = H, W273            if self.use_checkpoint:274                x = checkpoint.checkpoint(blk, x)275            else:276                x = blk(x)277        if self.downsample is not None:278            x_reshaped = x.transpose(1, 2).view(x.shape[0], x.shape[-1], H, W)279            x_down = self.downsample(x_reshaped)   280            x_down = x_down.flatten(2).transpose(1, 2)            281            Wh, Ww = (H + 1) // 2, (W + 1) // 2282            return x, H, W, x_down, Wh, Ww283        else:284            return x, H, W, x, H, W285 286 287class PatchEmbed(nn.Module):288    """ Image to Patch Embedding289 290    Args:291        patch_size (int): Patch token size. Default: 4.292        in_chans (int): Number of input image channels. Default: 3.293        embed_dim (int): Number of linear projection output channels. Default: 96.294        norm_layer (nn.Module, optional): Normalization layer. Default: None295        use_conv_embed (bool): Whether use overlapped convolution for patch embedding. Default: False296        is_stem (bool): Is the stem block or not. 297    """298 299    def __init__(self, patch_size=4, in_chans=3, embed_dim=96, norm_layer=None, use_conv_embed=False, is_stem=False):300        super().__init__()301        patch_size = to_2tuple(patch_size)302        self.patch_size = patch_size303 304        self.in_chans = in_chans305        self.embed_dim = embed_dim306 307        if use_conv_embed:308            # if we choose to use conv embedding, then we treat the stem and non-stem differently309            if is_stem:310                kernel_size = 7; padding = 2; stride = 4311            else:312                kernel_size = 3; padding = 1; stride = 2313            self.proj = nn.Conv2d(in_chans, embed_dim, kernel_size=kernel_size, stride=stride, padding=padding)                    314        else:315            self.proj = nn.Conv2d(in_chans, embed_dim, kernel_size=patch_size, stride=patch_size)316 317        if norm_layer is not None:318            self.norm = norm_layer(embed_dim)319        else:320            self.norm = None321 322    def forward(self, x):323        """Forward function."""324        _, _, H, W = x.size()325        if W % self.patch_size[1] != 0:326            x = F.pad(x, (0, self.patch_size[1] - W % self.patch_size[1]))327        if H % self.patch_size[0] != 0:328            x = F.pad(x, (0, 0, 0, self.patch_size[0] - H % self.patch_size[0]))329 330        x = self.proj(x)  # B C Wh Ww331        if self.norm is not None:332            Wh, Ww = x.size(2), x.size(3)333            x = x.flatten(2).transpose(1, 2)334            x = self.norm(x)335            x = x.transpose(1, 2).view(-1, self.embed_dim, Wh, Ww)336 337        return x338 339 340class FocalNet(nn.Module):341    """ FocalNet backbone.342 343    Args:344        pretrain_img_size (int): Input image size for training the pretrained model,345            used in absolute postion embedding. Default 224.346        patch_size (int | tuple(int)): Patch size. Default: 4.347        in_chans (int): Number of input image channels. Default: 3.348        embed_dim (int): Number of linear projection output channels. Default: 96.349        depths (tuple[int]): Depths of each Swin Transformer stage.350        mlp_ratio (float): Ratio of mlp hidden dim to embedding dim. Default: 4.351        drop_rate (float): Dropout rate.352        drop_path_rate (float): Stochastic depth rate. Default: 0.2.353        norm_layer (nn.Module): Normalization layer. Default: nn.LayerNorm.354        patch_norm (bool): If True, add normalization after patch embedding. Default: True.355        out_indices (Sequence[int]): Output from which stages.356        frozen_stages (int): Stages to be frozen (stop grad and set eval mode).357            -1 means not freezing any parameters.358        focal_levels (Sequence[int]): Number of focal levels at four stages359        focal_windows (Sequence[int]): Focal window sizes at first focal level at four stages360        use_conv_embed (bool): Whether use overlapped convolution for patch embedding361        use_checkpoint (bool): Whether to use checkpointing to save memory. Default: False.362    """363 364    def __init__(self,365                 pretrain_img_size=1600,366                 patch_size=4,367                 in_chans=3,368                 embed_dim=96,369                 depths=[2, 2, 6, 2],370                 mlp_ratio=4.,371                 drop_rate=0.,372                 drop_path_rate=0.2,373                 norm_layer=nn.LayerNorm,374                 patch_norm=True,375                 out_indices=[0, 1, 2, 3],376                 frozen_stages=-1,377                 focal_levels=[2,2,2,2], 378                 focal_windows=[9,9,9,9],379                 use_conv_embed=False, 380                 use_postln=False, 381                 use_postln_in_modulation=False, 382                 scaling_modulator=False,383                 use_layerscale=False, 384                 use_checkpoint=False, 385        ):386        super().__init__()387 388        self.pretrain_img_size = pretrain_img_size389        self.num_layers = len(depths)390        self.embed_dim = embed_dim391        self.patch_norm = patch_norm392        self.out_indices = out_indices393        self.frozen_stages = frozen_stages394 395        # split image into non-overlapping patches396        self.patch_embed = PatchEmbed(397            patch_size=patch_size, in_chans=in_chans, embed_dim=embed_dim,398            norm_layer=norm_layer if self.patch_norm else None, 399            use_conv_embed=use_conv_embed, is_stem=True)400 401        self.pos_drop = nn.Dropout(p=drop_rate)402 403        # stochastic depth404        dpr = [x.item() for x in torch.linspace(0, drop_path_rate, sum(depths))]  # stochastic depth decay rule405 406        # build layers407        self.layers = nn.ModuleList()408        for i_layer in range(self.num_layers):409            layer = BasicLayer(410                dim=int(embed_dim * 2 ** i_layer),411                depth=depths[i_layer],412                mlp_ratio=mlp_ratio,413                drop=drop_rate,414                drop_path=dpr[sum(depths[:i_layer]):sum(depths[:i_layer + 1])],415                norm_layer=norm_layer,416                downsample=PatchEmbed if (i_layer < self.num_layers - 1) else None,417                focal_window=focal_windows[i_layer], 418                focal_level=focal_levels[i_layer], 419                use_conv_embed=use_conv_embed,420                use_postln=use_postln, 421                use_postln_in_modulation=use_postln_in_modulation,422                scaling_modulator=scaling_modulator,423                use_layerscale=use_layerscale, 424                use_checkpoint=use_checkpoint)425            self.layers.append(layer)426 427        num_features = [int(embed_dim * 2 ** i) for i in range(self.num_layers)]428        self.num_features = num_features429 430        # add a norm layer for each output431        for i_layer in out_indices:432            layer = norm_layer(num_features[i_layer])433            layer_name = f'norm{i_layer}'434            self.add_module(layer_name, layer)435 436        self._freeze_stages()437 438    def _freeze_stages(self):439        if self.frozen_stages >= 0:440            self.patch_embed.eval()441            for param in self.patch_embed.parameters():442                param.requires_grad = False443 444        if self.frozen_stages >= 2:445            self.pos_drop.eval()446            for i in range(0, self.frozen_stages - 1):447                m = self.layers[i]448                m.eval()449                for param in m.parameters():450                    param.requires_grad = False451 452    def init_weights(self, pretrained=None):453        """Initialize the weights in backbone.454 455        Args:456            pretrained (str, optional): Path to pre-trained weights.457                Defaults to None.458        """459 460        def _init_weights(m):461            if isinstance(m, nn.Linear):462                trunc_normal_(m.weight, std=.02)463                if isinstance(m, nn.Linear) and m.bias is not None:464                    nn.init.constant_(m.bias, 0)465            elif isinstance(m, nn.LayerNorm):466                nn.init.constant_(m.bias, 0)467                nn.init.constant_(m.weight, 1.0)468 469        if isinstance(pretrained, str):470            self.apply(_init_weights)471            logger = get_root_logger()472            load_checkpoint(self, pretrained, strict=False, logger=logger)473        elif pretrained is None:474            self.apply(_init_weights)475        else:476            raise TypeError('pretrained must be a str or None')477 478    def load_weights(self, pretrained_dict=None, pretrained_layers=[], verbose=True):479        model_dict = self.state_dict()480 481        missed_dict = [k for k in model_dict.keys() if k not in pretrained_dict]482        logger.info(f'=> Missed keys {missed_dict}')483        unexpected_dict = [k for k in pretrained_dict.keys() if k not in model_dict]484        logger.info(f'=> Unexpected keys {unexpected_dict}')485 486        pretrained_dict = {487            k: v for k, v in pretrained_dict.items()488            if k in model_dict.keys()489        }490        491        need_init_state_dict = {}492        for k, v in pretrained_dict.items():493            need_init = (494                (495                    k.split('.')[0] in pretrained_layers496                    or pretrained_layers[0] == '*'497                )498                and 'relative_position_index' not in k499                and 'attn_mask' not in k500            )501 502            if need_init:503                # if verbose:504                #     logger.info(f'=> init {k} from {pretrained}')505 506                if ('pool_layers' in k) or ('focal_layers' in k) and v.size() != model_dict[k].size():507                    table_pretrained = v508                    table_current = model_dict[k]509                    fsize1 = table_pretrained.shape[2]510                    fsize2 = table_current.shape[2]511 512                    # NOTE: different from interpolation used in self-attention, we use padding or clipping for focal conv513                    if fsize1 < fsize2:514                        table_pretrained_resized = torch.zeros(table_current.shape)515                        table_pretrained_resized[:, :, (fsize2-fsize1)//2:-(fsize2-fsize1)//2, (fsize2-fsize1)//2:-(fsize2-fsize1)//2] = table_pretrained516                        v = table_pretrained_resized517                    elif fsize1 > fsize2:518                        table_pretrained_resized = table_pretrained[:, :, (fsize1-fsize2)//2:-(fsize1-fsize2)//2, (fsize1-fsize2)//2:-(fsize1-fsize2)//2]519                        v = table_pretrained_resized520 521 522                if ("modulation.f" in k or "pre_conv" in k): 523                    table_pretrained = v524                    table_current = model_dict[k]525                    if table_pretrained.shape != table_current.shape:526                        if len(table_pretrained.shape) == 2:527                            dim = table_pretrained.shape[1]528                            assert table_current.shape[1] == dim529                            L1 = table_pretrained.shape[0]530                            L2 = table_current.shape[0]531 532                            if L1 < L2:533                                table_pretrained_resized = torch.zeros(table_current.shape)534                                # copy for linear project535                                table_pretrained_resized[:2*dim] = table_pretrained[:2*dim]536                                # copy for global token gating537                                table_pretrained_resized[-1] = table_pretrained[-1]538                                # copy for first multiple focal levels539                                table_pretrained_resized[2*dim:2*dim+(L1-2*dim-1)] = table_pretrained[2*dim:-1]540                                # reassign pretrained weights541                                v = table_pretrained_resized542                            elif L1 > L2:543                                raise NotImplementedError544                        elif len(table_pretrained.shape) == 1:545                            dim = table_pretrained.shape[0]546                            L1 = table_pretrained.shape[0]547                            L2 = table_current.shape[0]548                            if L1 < L2:549                                table_pretrained_resized = torch.zeros(table_current.shape)550                                # copy for linear project551                                table_pretrained_resized[:dim] = table_pretrained[:dim]552                                # copy for global token gating553                                table_pretrained_resized[-1] = table_pretrained[-1]554                                # copy for first multiple focal levels555                                # table_pretrained_resized[dim:2*dim+(L1-2*dim-1)] = table_pretrained[2*dim:-1]556                                # reassign pretrained weights557                                v = table_pretrained_resized558                            elif L1 > L2:559                                raise NotImplementedError    560 561                need_init_state_dict[k] = v562        563        self.load_state_dict(need_init_state_dict, strict=False)564 565 566    def forward(self, x):567        """Forward function."""568        tic = time.time()569        x = self.patch_embed(x)570        Wh, Ww = x.size(2), x.size(3)571 572        x = x.flatten(2).transpose(1, 2)573        x = self.pos_drop(x)574 575        outs = {}576        for i in range(self.num_layers):577            layer = self.layers[i]578            x_out, H, W, x, Wh, Ww = layer(x, Wh, Ww)579            if i in self.out_indices:580                norm_layer = getattr(self, f'norm{i}')581                x_out = norm_layer(x_out)582 583                out = x_out.view(-1, H, W, self.num_features[i]).permute(0, 3, 1, 2).contiguous()584                outs["res{}".format(i + 2)] = out585                586        if len(self.out_indices) == 0:587            outs["res5"] = x_out.view(-1, H, W, self.num_features[i]).permute(0, 3, 1, 2).contiguous()588 589        toc = time.time()590        return outs591 592    def train(self, mode=True):593        """Convert the model into training mode while keep layers freezed."""594        super(FocalNet, self).train(mode)595        self._freeze_stages()596 597 598class D2FocalNet(FocalNet, Backbone):599    def __init__(self, cfg, input_shape):600 601        pretrain_img_size = cfg['BACKBONE']['FOCAL']['PRETRAIN_IMG_SIZE']602        patch_size = cfg['BACKBONE']['FOCAL']['PATCH_SIZE']603        in_chans = 3604        embed_dim = cfg['BACKBONE']['FOCAL']['EMBED_DIM']605        depths = cfg['BACKBONE']['FOCAL']['DEPTHS']606        mlp_ratio = cfg['BACKBONE']['FOCAL']['MLP_RATIO']607        drop_rate = cfg['BACKBONE']['FOCAL']['DROP_RATE']608        drop_path_rate = cfg['BACKBONE']['FOCAL']['DROP_PATH_RATE']609        norm_layer = nn.LayerNorm610        patch_norm = cfg['BACKBONE']['FOCAL']['PATCH_NORM']611        use_checkpoint = cfg['BACKBONE']['FOCAL']['USE_CHECKPOINT']612        out_indices = cfg['BACKBONE']['FOCAL']['OUT_INDICES']613        scaling_modulator = cfg['BACKBONE']['FOCAL'].get('SCALING_MODULATOR', False)614 615        super().__init__(616            pretrain_img_size,617            patch_size,618            in_chans,619            embed_dim,620            depths,621            mlp_ratio,622            drop_rate,623            drop_path_rate,624            norm_layer,625            patch_norm,626            out_indices,627            focal_levels=cfg['BACKBONE']['FOCAL']['FOCAL_LEVELS'],628            focal_windows=cfg['BACKBONE']['FOCAL']['FOCAL_WINDOWS'],   629            use_conv_embed=cfg['BACKBONE']['FOCAL']['USE_CONV_EMBED'],    630            use_postln=cfg['BACKBONE']['FOCAL']['USE_POSTLN'],       631            use_postln_in_modulation=cfg['BACKBONE']['FOCAL']['USE_POSTLN_IN_MODULATION'], 632            scaling_modulator=scaling_modulator,633            use_layerscale=cfg['BACKBONE']['FOCAL']['USE_LAYERSCALE'], 634            use_checkpoint=use_checkpoint,635        )636 637        self._out_features = cfg['BACKBONE']['FOCAL']['OUT_FEATURES']638 639        self._out_feature_strides = {640            "res2": 4,641            "res3": 8,642            "res4": 16,643            "res5": 32,644        }645        self._out_feature_channels = {646            "res2": self.num_features[0],647            "res3": self.num_features[1],648            "res4": self.num_features[2],649            "res5": self.num_features[3],650        }651 652    def forward(self, x):653        """654        Args:655            x: Tensor of shape (N,C,H,W). H, W must be a multiple of ``self.size_divisibility``.656        Returns:657            dict[str->Tensor]: names and the corresponding features658        """659        assert (660            x.dim() == 4661        ), f"SwinTransformer takes an input of shape (N, C, H, W). Got {x.shape} instead!"662        outputs = {}663        y = super().forward(x)664        for k in y.keys():665            if k in self._out_features:666                outputs[k] = y[k]667        return outputs668 669    def output_shape(self):670        return {671            name: ShapeSpec(672                channels=self._out_feature_channels[name], stride=self._out_feature_strides[name]673            )674            for name in self._out_features675        }676 677    @property678    def size_divisibility(self):679        return 32680 681@register_backbone682def get_focal_backbone(cfg):683    focal = D2FocalNet(cfg['MODEL'], 224)    684 685    if cfg['MODEL']['BACKBONE']['LOAD_PRETRAINED'] is True:686        filename = cfg['MODEL']['BACKBONE']['PRETRAINED']687        logger.info(f'=> init from {filename}')688        with PathManager.open(filename, "rb") as f:689            ckpt = torch.load(f)['model']690        focal.load_weights(ckpt, cfg['MODEL']['BACKBONE']['FOCAL'].get('PRETRAINED_LAYERS', ['*']), cfg['VERBOSE'])691 692    return focal